Tool for binding cable harnesses



Feb. 17, 1970 H. KABEL 95.3

'rooL FOR BINDING CABLE HARNESSES- Filed Nov. 4, i968 layer/[0r Hem! mall K4551. Y

? bezsoe srE/N n53.2-

United States Patent 3,495,389 TOOL FOR BINDING CABLE HARNESSES Heinrich Kabel, Quickborn, Holstein, Germany, assignor to Paul Hellermann G.m.h.H., Pinneberg, Germany Filed Nov. 4, 1968, Ser. No. 773,233 Claims priority, application Germany, Nov. 14, 1967,

Int. ci. Din 3/36 US. Cl. 57-3 2 Claims ABSTRACT OF THE DISCLOSURE In an appliance for binding cable assemblies with a strap, the strap is carried on a reel fixed in relation to a rotatable shaft, and the strap is tensioned by rotating the shaft. In order to limit the tension, the strap passes over a cam which deflects the strap from a straight path. The cam is connected to a ratchet and, when moved by tensioning of the strap, moves the ratchet against an adjustable spring force into engagement with a toothed gear wheel fixed to the rotatable shaft and thereby prevents further'rotation of the shaft.

This invention relates to an appliance for binding cable assemblies etc. with a strap placed around and closely adjacent to the cable assembly, the ends of which strap, after tensioning of the strap, are held by a lock member which appliance has a reel of strap, fixed in relation to a rotatable shaft, a device for guiding the strap to the lock member to be closed, a device for turning the shaft for the tensioning of the strap and an appliance for limiting the tension.

For such appliances it is known to prevent overstressing of the strap by means of a slip clutch arranged between the rotatable shaft, on which the reel of strap is placed, and a device for rotating the shaft. If a given torque is applied to the slip clutch then a corresponding tension is produced in the strap and prevents tearing of the strap. It has however the disadvantage that according to the length of strap wound on and the diameter of the reel necessarily made to differ by this, the tension of the strap determined by the slipping clutch is likewise different. That is to say, that in the case of small diameter it is greater, on account of the smaller radius acting as a lever arm, than in the case of a large diameter of the roll of strap on the reel. If it is not desired to constantly adjust the torque applied to the slip clutch with the decrease in the diameter of the reel of strap, it is necessary to provide a torque adapted to the minimum diameter of the reel of strap, in which case the largest pull in the strap is produced, and thereby it is to be taken in consideration that, in the case of a large strap reel diameter, the slip clutch responds, even if the pull on the strap has not yet reached the permissible limit. This however has the disadvantage that then necessary strap tension is possibly not reached at all. Furthermore the known device takes up a lot of space.

An object of the invention is to provide a device for limiting the strap tension in the case of an appliance of the type mentioned at the beginning, which even with varying diameter of the strap reel determines a substantially constant limiting tension for the strap and is easier to accommodate spatially in the implement.

This object of the invention is achieved, in that in the path of the strap in the guide direction, there is provided a movably supported cam, which deflects the strip under spring tension from a straight path, which cam is connected with a ratchet, which with the movement of the cam under tensioning of the strap against the spring tension comes into engagement with a gear wheel rigidly connected with the shaft.

By means of the invention it is achieved that the tension in each case is detected directly in the strap and that the securing of the strap against overstressing is not dependent on the diameter of the strap reel at the time. Moreover only structural elements of the simplest type are needed.

An adjustment of the highest permissible tension can advantageously be effected, in that the cam is connected via a lever arm with the spring and can be adjusted on this lever arm.

The invention will now be described in greater detail by way of example with reference to the accompanying drawing, which shows a longitudinal section through the rear part of an appliance with the reel of strap and the tension limiting device.

The drawing illustrates a device for limiting the tension of the strap which prevents altogether excessive tensioning and thus overstressing of the strap and tension apparatus. From a reel 1, which is fixed in relation to a rotatable shaft 2 and can !be turned by means of a control knob situated on the shaft 2, a strap 3 runs through guides 4 and 5 to the locking device (not shown). The belt 3 is deflected from a straight path by a cam 6 carried by a rod 7, which is pivotally supported at 8 in the body of the implement 9. The rod 7 is formed as a twoarmed lever and has a lever extension 10, which is connected with a slider 11, having slots 12 which engage pins 13 fixed to the housing to ensure the guidance of the slider. The slider 11 carries a ratchet 14, which is situated adjacent the periphery of a gear wheel 15, which is fixed for rotation with the shaft 2. The slider 11 is biased by a spring 16 into a position removed from the gear wheel 15. The cam 6 can be adjusted on the rod 7 for altering the leverage and thus for varying the force limit.

The appliance works in the following Way:

The strap 3 is tensioned by turning the shaft 2. As long as the tensioning of the strap 3 remains below a given limit value, the slide 11 remains under the influence of the spring 16 in the rest position with the ratchet 14 out of the path of the gear wheel 15. However if the component of the belt tension acting on the cam 6 exceeds the counteracting force of the spring 16, then the cam 6 is pressed down and the slider 11 is pushed to the left in the drawing, whereby the ratchet 14 comes into engagement with the teeth of the gear wheel 15, whereafter further tensioning movement of the shaft 2 is prevented.

I claim:

1. In an appliance for binding cable assemblies etc. with a strap placed around and closely adjacent to the cable assembly, the ends of which strap, after tensioning of the strap, are held by a lock member, said appliance comprising:

(a) a rotatable shaft,

(b) a strap reel arranged for rotation with said shaft,

(c) means for guiding strap from said reel along a path to the lock member,

(d) means for turning said shaft for tensioning said strap, and

(e) means for limiting the tension, the improvement 3 4- (f) a cam means movably supported in the path of References Cited mvefnent UNITED sTATEs PATENTS (g) sprlng means actmg on sand cam to cause said cam I to defiect the strap from a straight path, i 2,253,740 8/1941 XR (h) a gear Wheel rigidly connected with shaft,and 5 1953 z-Anglolmo et XR (i) 'a ratchet 'connected with said cam, whereby move- 3,009,136 1U/1961 GT et ment of the cam under tensioning of the strap moves 5,963,228 11/1962 Sarraclns said ratchet into engagement with said gear Wheel. JOHN PETRAKES Primary Examiner 2. An appliance as claimed in claim 1, wherein said' j a cam is connected with said spring means by Way of a 10 US. Cl. X.-R.

lever arm, and can be adjusted on said lever arm. 574-19 

